FIG. 7 is a partial cross-sectional view of prior art torque converter 200. Torque converter 200 includes: axis of rotation AR; cover 202 arranged to receive torque from an engine (not shown), for example in circumferential direction CD1 for a drive mode; impeller 204 non-rotatably connected to cover 202; turbine 206 in fluid communication with impeller 204; torque converter clutch 208 including piston 210; and vibration damper 212. Damper 212 includes: cover plates 214A and 214B connected to torque converter clutch 208; output flange 216; and at least one spring 218 engaged with cover plates 214A and 214B and output flange 216.
For a lockup mode, clutch 208 is closed. In a coast mode for torque converter 200, turbine 206 rotates faster than cover 202. As a result, fluid in chamber 218 rotates faster than fluid in chamber 220. This pressure differential will result in lower pressure in chamber 220, pulling piston 210 in direction AD1, undesirably preventing clutch 208 from remaining closed. To prevent this pressure differential, seal 222 is installed in chamber 218. Seal 222 blocks the fluid flow associated with the undesirable pressure differential. However, seal 222 adds to the cost and complexity of torque converter. Further, seal 222 reduces the overall durability of torque converter 200.